Headlamps are used in a large number of activities, including professional activities, sports and games.
Generally speaking, these lamps are intended to allow a “hand free” type of lighting which should be efficient, comfortable and ensuring maximum battery life.
The trend has been, for many years, to increase the functionality of the new headlamps.
The present application has introduced the concept of so-called “dynamic” lighting, with the use of a regulation of the power of the light emitted by the lamp, unlike a so-called “static” mode wherein the lamp produces constant power. Patent application FR2930706 dated Apr. 24, 2008 describes a self-regulated lighting lamp which uses a light sensor for sensing the light reflected by an object illuminated by the lamp for the purpose of controlling the regulation of the intensity of the light. FIG. 1 illustrates such a lamp that includes an optical sensor 14 located in the housing in the vicinity of the light-emitting diode LED 11 for outputting a signal being representative of the light reflected by the surface of an object 16 being illuminated by the lamp. The signal is transmitted to a second input of a controller 13 for automatically controlling the power of the LED according to a predetermined threshold. In this manner, automatic control of the light beam emitted by the lamp is achieved without requiring any manual action to adjust the lighting in the environment, while managing the power consumption.
Such conventional lamp has been improved by the provision of multiple LEDs to produce separate beams respectively wide and narrow, providing great flexibility to users of this lamp, which can thus benefit from strong light to see “afar” but also comfortable viewing “closely.”
This lamp shows a significant success especially within sports communities, including rock climbing, hiking and running . . . .
However it has appeared that the so-called dynamic regulation system is difficult to implement because it tends to be easily disturbed by light echoes that interfere differently for a “far” vision with a narrow beam or a “close” vision with a wide beam.